From e4d271289733847ee21c6940cba36a6784dd853d Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Tue, 23 Apr 2019 20:49:45 -0700
Subject: [PATCH] Mp3: Apply offset to stream read buffer.

Handle errors for sceMp3CheckStreamDataNeeded as well.
---
 Core/HLE/sceMp3.cpp        | 19 +++++++++++--------
 Core/HW/SimpleAudioDec.cpp | 18 ++++++++++++------
 Core/HW/SimpleAudioDec.h   |  1 +
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/Core/HLE/sceMp3.cpp b/Core/HLE/sceMp3.cpp
index a474d91ec9..7ffb6e4711 100644
--- a/Core/HLE/sceMp3.cpp
+++ b/Core/HLE/sceMp3.cpp
@@ -181,15 +181,16 @@ static int sceMp3ResetPlayPosition(u32 mp3) {
 }
 
 static int sceMp3CheckStreamDataNeeded(u32 mp3) {
-	DEBUG_LOG(ME, "sceMp3CheckStreamDataNeeded(%08x)", mp3);
-
 	AuCtx *ctx = getMp3Ctx(mp3);
 	if (!ctx) {
-		ERROR_LOG(ME, "%s: bad mp3 handle %08x", __FUNCTION__, mp3);
-		return -1;
+		if (mp3 >= MP3_MAX_HANDLES)
+			return hleLogError(ME, ERROR_MP3_INVALID_HANDLE, "invalid handle");
+		return hleLogError(ME, ERROR_MP3_UNRESERVED_HANDLE, "unreserved handle");
+	} else if (ctx->AuBuf == 0) {
+		return hleLogError(ME, ERROR_MP3_UNRESERVED_HANDLE, "incorrect handle type");
 	}
 
-	return ctx->AuCheckStreamDataNeeded();
+	return hleLogSuccessI(ME, ctx->AuCheckStreamDataNeeded());
 }
 
 static u32 sceMp3ReserveMp3Handle(u32 mp3Addr) {
@@ -344,15 +345,17 @@ static int __CalculateMp3Bitrates(int bitval, int mp3version, int mp3layer) {
 }
 
 static int __ParseMp3Header(AuCtx *ctx, bool *isID3) {
-	int header = bswap32(Memory::Read_U32(ctx->AuBuf));
+	u32 ptr = ctx->AuBuf + ctx->AuStreamWorkareaSize();
+	int header = bswap32(Memory::Read_U32(ptr));
 	// ID3 tag , can be seen in Hanayaka Nari Wa ga Ichizoku.
 	static const int ID3 = 0x49443300;
 	if ((header & 0xFFFFFF00) == ID3) {
 		*isID3 = true;
-		int size = bswap32(Memory::Read_U32(ctx->AuBuf + ctx->startPos + 6));
+		// TODO: Can we count on startPos being read already?  What if it's past the buffer size?
+		int size = bswap32(Memory::Read_U32(ptr + ctx->startPos + 6));
 		// Highest bit of each byte has to be ignored (format: 0x7F7F7F7F)
 		size = (size & 0x7F) | ((size & 0x7F00) >> 1) | ((size & 0x7F0000) >> 2) | ((size & 0x7F000000) >> 3);
-		header = bswap32(Memory::Read_U32(ctx->AuBuf + ctx->startPos + 10 + size));
+		header = bswap32(Memory::Read_U32(ptr + ctx->startPos + 10 + size));
 	}
 	return header;
 }
diff --git a/Core/HW/SimpleAudioDec.cpp b/Core/HW/SimpleAudioDec.cpp
index 4a26c01999..b8062ca56e 100644
--- a/Core/HW/SimpleAudioDec.cpp
+++ b/Core/HW/SimpleAudioDec.cpp
@@ -397,7 +397,7 @@ int AuCtx::AuStreamBytesNeeded() {
 		if (readPos >= endPos)
 			return 0;
 		// Account for the workarea.
-		int offset = 0x05c0;
+		int offset = AuStreamWorkareaSize();
 		return (int)AuBufSize - AuBufAvailable - offset;
 	}
 
@@ -405,8 +405,17 @@ int AuCtx::AuStreamBytesNeeded() {
 	return std::min((int)AuBufSize - AuBufAvailable, (int)endPos - readPos);
 }
 
+int AuCtx::AuStreamWorkareaSize() {
+	// Note that this is 31 bytes more than the max layer 3 frame size.
+	if (audioType == PSP_CODEC_MP3)
+		return 0x05c0;
+	return 0;
+}
+
 // check how many bytes we have read from source file
 u32 AuCtx::AuNotifyAddStreamData(int size) {
+	int offset = AuStreamWorkareaSize();
+
 	if (askedReadSize != 0) {
 		// Old save state, numbers already adjusted.
 		int diffsize = size - askedReadSize;
@@ -422,7 +431,7 @@ u32 AuCtx::AuNotifyAddStreamData(int size) {
 	}
 
 	if (Memory::IsValidRange(AuBuf, size)) {
-		sourcebuff.append((const char *)Memory::GetPointer(AuBuf), size);
+		sourcebuff.append((const char *)Memory::GetPointer(AuBuf + offset), size);
 	}
 
 	if (readPos >= (int)endPos && LoopNum != 0) {
@@ -441,10 +450,7 @@ u32 AuCtx::AuNotifyAddStreamData(int size) {
 // buff, size and srcPos are all pointers
 u32 AuCtx::AuGetInfoToAddStreamData(u32 bufPtr, u32 sizePtr, u32 srcPosPtr) {
 	int readsize = AuStreamBytesNeeded();
-	int offset = 0;
-	if (audioType == PSP_CODEC_MP3) {
-		offset = 0x05c0;
-	}
+	int offset = AuStreamWorkareaSize();
 
 	// we can recharge AuBuf from its beginning
 	if (readsize != 0) {
diff --git a/Core/HW/SimpleAudioDec.h b/Core/HW/SimpleAudioDec.h
index 182d2dc7bf..c41707c3a5 100644
--- a/Core/HW/SimpleAudioDec.h
+++ b/Core/HW/SimpleAudioDec.h
@@ -100,6 +100,7 @@ public:
 	u32 AuNotifyAddStreamData(int size);
 	int AuCheckStreamDataNeeded();
 	int AuStreamBytesNeeded();
+	int AuStreamWorkareaSize();
 	u32 AuResetPlayPosition();
 	u32 AuResetPlayPositionByFrame(int position);